9 November 1974 S.-A. MEDIESE lYDSKRlf 2265 The Use of Mebendazole as a Broad-Spectrum Anthelmintic in Rhodesia

J. M. GOLDSMID

SUMMARY varying in age from I to 40 years. In all specie? of helminth a dose of 100 mg mebenda­ In a trial on baboons and humans, mebendazole was found zole b.d. for 3 days was used, except in the case of EnTero­ to be a very safe and highly effective anthelmintic for billS vermicularis, where the dose was 100 mg once only. a range of intestinal helminths in Central Africa, including After treatment, follow-up was carried out on all sub­ hookworm (Ancylostoma duodenale and Necator ameri­ jects for 7 - 10 days and, whenever possible, for longer canus), Oesophagostomum bifurcum, Ternidens deminutus, .periods. In the case of E. vermicu{aris, follow-up after Strongyloides stercoralis, Strongyloides fiilleborni, Physa­ treatment consisted of I - 6 anal tal?es, while in all other loptera (=. Abbreviata) sp., Ascaris lumbricoides, Entero­ speCIes, follow-up consisted of stools examined by water bius vermicularis, Trichuris trichiura, Taenia saginata and centrifugation and NaCI flotation. In the case of a single Moniliformis moniliformis. It has also some activity against Taenia saginata infection included in the study, species Hymenolepis nana. identification was based on the recovery of proglottids, and follow-up was continued for one year. Hookworm S. AII'. Med. J., 48, 2265 (1974). infections were separated from those of Ternidens deminll­ 1o In recent years many new anthelmintics have been deve­ tllS on the basis of egg size as outlined by Goldsmid:· loped against intestinal helminths, including bephenium Pretreatment egg counts and, where necessary, post­ hydroxynaphthoate, tetramisole, levamisole, thiabendazole treatment egg counts were done, using the Stoll Dilution and pyrantel pamoate. The trend has been to develop Egg Counting technique. drugs firstly to be effective and to have as broad an anthel­ Note was kept of any side-effects which occurred. . mintic action as possible, and secondly, to have a minimum of side-effects. Thus bephenium hydroxynapthoate, al­ RESULTS though safe, had a relatively limited species-efficacy; tetramisole and levamisole were fairly broad-spectrum and The results of the study are given in Tables I and n. Cure relatively free from side-effects; pyrantel pamoate, too, was assessed as proved if no eggs were recovered 7 - 10 was fairly broad-spectrum and caused very few and very days after treatment. mild side-effects. On the other hand, although thiabenda­ zole was effective against a wide range of intestinal nema­ TABLE L RESULTS OF TREATMENT OF 25 BABOONS todes, its side-effects were relatively unpleasant and pre­ cluded its use as a widely used anthelmintic.'" (PAPIO U~SINUS) FOR INTESTINAL NEMATODES Recently, a new anthelmintic was marketed and report­ WITH MEBENDAZOLE ed to be effective for the treatment of a variety of in­ Species Treated Cured testinal nematodes and some cestodes. Thus it was reported to be very effective against Ascaris lumbricoides, Entero­ Strongyloides tiilleborni* 11 11 bius vermicularis, and the hookworms, Trichuris trichiura Oesophagostomum bifurcum* 10 10 and even Taenia saginata.'·s Physaloptera (= Abbreviata) sp.* 3 3 A trial was designed to test the value of this new drug, Streptophargus pigmentatus 1 1 mebendazole (methyl-5-benzoylbenzimidazole - 2 - carba­ mate, RI7, 635; Vermox) as a broad-spectrum anthelmin­ Total 25 25 (100%) tic against a variety of intestinal helminth species in 11' Also recorded from humans. Rhodesia. Those cases where longer follow-up proved 'cure' are METHODS summarised in Table HI, which also shows that no relapses were recorded. After initial trials were carried out on baboons (Papio No side-effects were reported in any of the patients. ursinus), subsequent studies were performed on humans DISCUSSION Department of Medical Microbiology, University of Rhodesia, Salisbury, Rhodesia As seen from the results. mebendazole was found to be J. M. GOLDSMID an extremely safe and highly effective anthelmintic against Date received: 1 August 1974. a wide range of intestinal helminths which infect man. Paper read at the 3rd International Congress of Parasitology, ~1unich. 29 August 1974. confirming earlier studies. S.A. MEDICAL JOURNAL: 9.th Nov.emh'" 1'<.7.<1

2266 S.A. MEDICAL JOURNAL 9 November 1974

TABLE 11. RESULTS OF TREATMENT OF 102 HUMANS FOR todes and acanthocephala, and the complete absence of INTES1INAL HELMINTHS (NEMATODES, CESTODES AND side-effects, this drug must certainly rank as the biggest breakthrough in anthelmintic drug development to date, ACANTHOCEPHALA WITH MEBENDAZOLE a conclusion endorsed by Sargent et al." who state that, for trichuriasis, mebendazole 'surpasses all currently avail­ Species Cured Treated able drug therapy in the USA'. Hookworm 29 ( 97%)* 30 Ternidens deminutus i8 (lOOOo) 18 Advantages of Mebendazole Enterobius vermicularis 13 (100%) 13 Ascaris lumbricoides 13 (100%) 10 With its broad spectrum, high rate of cure and complete Strongyloides stercoralis 7 ( 88°~) 8 safety (especially if established for pregnant women), it Trichuris trichiura 6(1000~} 6 permits mass outpatient treatment without the prior need Hymenolepis nana 6 (40%) 15 for laboratory screening. Taenia saginata 1 1 Because of its efficacy and safety, routine anthelmintic Moniliformis moniliformis" 1 1 treatment of staff (e.g. on sugar estates) becomes possible. Total It can also be used in small rural clinics without labora­ 102 tory facilities. • In the one hookworm case not cured. a reduction in worm load of It is not suggested that laboratory examinations of the 50% was achieved. stool should be dispensed with, or that the treatment of patients, without first establishing which species of in­ testinal helminth is involved, is desirable. It is suggested, however, that where laboratory facilities are non-existent, TABLE Ill. LONG-TERM POST-TR~ATMENT FOLLOW-UP ON or where cost precludes a prior stool examination (or mul­ PATIENTS CURED OF VARIOUS INTESTINAL HELMINTHS tiple stool examinations), this drug can be used to advan­ tage - even with a view to treating entire, unscreened Species Length of follow-up No. negative communities to break the cycle of transmission in endemic areas in association with the other usual prophylactic Hookworm 3 - 4 weeks 2 measures, e.g. education, hygiene, provision of toilets, wear­ 6 weeks 2 ing of shoes, etc. 6 months 1 9 months 1 I wish to thank Ethnor Laboratories for supplying the T. deminutus 3 - 4 weeks 5 mebendazole (Vermox) used in this trial. T. trichiura 3 - 4 weeks 2 A lumbricoides 3 - 4 weeks 1 REFERENCES T. saginata >1 year 1 M. moniliformis >1 year 1 L Desowitz. R. S. (1971): Ann. Rev. Pharmacal.. 11, 35L 2. Goldsmid, 1. M. (1972): S. Afr. Med. l .. 46, 1046. 3. Brugmans, J. P., Th.enpont. D. C.. Van Wijngaarden. I.. Vanparijs, O. F., Schuermans, V. L. and Lauwers, H. L. (1971): l. Amer. Med. Assoc., 217, 313. In fact, of all the species for which this drug was tested, 4. Chaia, G. and Da Cunha. A. S. (1971): F61ha Medica, 63, 67. in only one, Hymenolepis nana, was there not an almost 5. Chavarria, P. A .. Swanzwelder, J. C., Vilarejos. V. M. and Zeled6n. R. (1973): Amer. J. Trap. Med. Hyg., 22, 592. 100% cure rate. In H. nana, at the dosage used, the drug 6. Banerjee. D .. Mandal, A. and Prakash, O. (1971): Trans. Ray. Soc. Trap. Med. Hyg., 65, 685. only achieved a 40% cure rate. 7. Wagner, E. D. and Chavarria. A. P. (1974): Amer. l. Trap. Med. If one includes H. nana in the series, a cure rate of 89°~ Hyg.. 23, 151. 8. Idem (1974): [bid., 23, 154. for helminths ranging from cestodes to acanthocephala, 9. Go1dsmid. J. M. (1968): Trans. Ray. Soc. Trap. Med. Hyg.. 62, 109. 10. Idem (1971): Ternidens deminutus: A ParasitoIogical Enigma in was achieved. Excluding H. nana, the cure rate was a Rhodesia. Res. Lect. Series. No. 4. Salisbury: Faculty of Medicine, 100o~ University of Rhodesia. remarkable 98% in the human trial and in the 11. Goldsmid. J. M., Ewart-Smith. M. and Fleming. F. (1974): Ann. baboon trial. With such a high rate of cure for over 13 Trap. Med. Parasit. (in press) 12. Sargent, R. G .. Savory, A. M., Mina, A. and Lee, P. R. (1974): species of intestinal helminths, including cestodes, nema- Amer. l. Trap. Med. Hyg.. 23, 375.